Method of expanding stranded sheet metal.



METHOD OF EXPANDING STRAN D E D S H E E T M E T A L.

AAAAAAAAAAAAAAAAA us. 29. 1913. T 1 33l $88 Patented July 3, 1917.

I 2 SHE EEEEEEEEE l- H. C, HEBR.

METHOD OF EXPANDING STRANDED SHEET METAL.

APPLICATION FILED AUGIZQ, I911}.

?atentedlu1y3, 191?.

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- result ma panded and UNITED ST TO SOUTH SIDE 'II'RUS'I COMPANY,

METHOD OF EXPANDING STRANDED SHEET METAL.

Application filed August 29, 1913. Serial No. 787,388.

To all whom it mag/concern:

Be it known that I, HENRY C. Human citizen of the United States of America, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Methods for Expanding Stranded Sheet Metal, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to the manufacture of expanded sheet metal, and has particular reference to the novel method of expanding a stranded sheet, as hereinafter set forth.

In the drawings:

Figure 1 is a plan view of the stranded sheet, showing the manner of slitting and expanding the same;

Fig. 2 is a cross section through the stranded sheet in engagement with the expanding device; v

Fig. 3 is a longitudinal section, illustratin one step in the expanding operation;

liig. 4 is a diagrammatic view of the sheet, showing the successive operations in expandingl the same;

ig. 5 is a plan view'of a fragment of the completed product Fig. 6 is a similar struction, and

Fig. 7 1s a cross section thereof. 7

In the art of expanding sheet metal as usually practised, anincident of the lateral View of a modified conexpansion of the sheet is the longitudinal contraction thereof; but this resultis not objectionable in the production of expanded metal for ordinary purposes. -For special purposes, however, only a portion of where this is done it is desirable to expand the original blank, and difliculty is experienced in preventing the buckling of the unexpanded portion, due to the longitudinal conexpanded portion. Such a be avoided by the elongation of s to compensate for'their lateral but a new diiiiculty results from the weakening of the structure the division line between the exunexpanded portions. 4

the stra'n deflection this viz., adjacent to Specification oi Letters Patent.

Patented July a; rear.

The present invention come this difliculty by ing the stranded sheet, and the invention consists, first, in the method of producinga progressive or differential expansion; and second, in the production of this result by successlve step-by-step expansion of different portions of the sheet.

In detail, A is a sheet metalblank, which is stranded, preferably, by first slitting with alined bonds B, and then re-slitting centrally of the strands to produce staggered bonds B, the opposite margins D of the blank being left unslitted. Y x stranding operation, the sheet is bent to deflect alternate strands into different planes, as shown at O and C in Fig. 2. The expani s an incident of the sion of the stranded sheet is accomplished by a series of successive operations,

, which produce after each partial expansion an elongation of the strands, permitting of further exremoved-from the unexpanded portion, while the. least expansion is immedia to the unexpan'ded portion;

ely adjacent center of the sheet, or at the point farthest Asshown in Fig.1, the primary expansion of the sheetls effected site edges thereof inopposite directions, as for instanceby engaging said edges of the sheet avith grippers E secured to traveling allel to the direction of travel of the chains F, and thus the initial expansion is confined to the portion of the stranded blank between by drawing the oppo-I chains F, which travel in divergent planes.

unslittedmiargins D thereof,

' margins.

said aides and does not extend to thaportions etween the guides and the unstranded -A'fterthis first expanding step, the porswtion of the hlankthixs-expanded 1S operated r-hpon to elongate the strandsflthereof, so as permit of further expansiomthis elongation being preferably accomplishdd by passpended from themargin to the center.

central I portions, the total result being a diii'ercntial expansion, progressively increasmg in the direction from the marg n toward the center.

The alternate operations of expanding the] central and marginal portions'of the sheet continue until the full degree of expansion 1's attained, after which the sheet is passed ,through crowned rolls J, which harmonize l the thickness of the sheet to the differential expansion thereof and deliver it in flattened condition. f The product is illustrated in Fig. 7, and as indicated, isprogressivelytex- By expanding sheet metal in the manner described, theoverstressing of any portion of theblank is avoided, and furthermore the product obtained is one which is free from all of the defects common to expanded sheets which has unexpanded portions.

den change in either the direction or the gage of the strands, and consequently a weak line inthe sheet is avoided. A'still greater strength is obtained by progressively changing the width of the strands,

I with the widest strands nearest the, un-

stranded portion, as shown in Fig. 6.

I claim,

1. The method of expanding stranded sheet metal, comprising the constant expansion of a sheet, and the SUCCGSSlWE expansion of constituent portions of said sheet.

p 2-. The method of expanding sheet metal,

' comprising the constant separation of op posite margins of a stranded sheet, and the ili'erentialelongation of the strands to form a progressive expansion.

2-5. The method of expanding sheet metal,- comprising the successive lateral expansion of portions of a stranded sheet, and the elongation of the strands "if one portion during the interval in which they are not laterally expanded. I

4.. Themethcd'of expandingsheetmetal,

, comprising the forming from'lateral expansion.

-.intermittent guiding of the stranded portion of said sheet to confine the expansion to a portion thereof, and the successive ro1l-- ing of said portion; to elongate the strands 100 sion.

comprisingthe. constant lateral expansion of a stranded sheet, with successive lateral expansion 1 of constituent portions thereof, and the elongation of the strands of one portionv durin the interval in which they are not latera y expanded.

5. The method ,of forming expanded metal, comprising the difierential stranding. of the sheet'and subsequent constant lateral expansion of said sheet, With successive expension of constituent portions thereof and elongation of the strands.

6. The method of expanding. sheet metal,

I of a sheet with stranded and unstrand subsequent expansion of the stranded porportions, and the D tion ofs'e'idjsheet progressivelyffrom the' unstranded: portions thereof.

- 7. The method of expanding metal, coinprising the drawing apart ofzoppositeed es I I said "'sheet.'

of, a stranded sheet, and the successive ho d; ing of constituent portions of 8; The method'of expanding sheet,i net al, I comprising the constant separationfofo posite edges ofxastrandedsheet, and t e intermittent rolling of a. portion of said sheet to elongate the strands thereof.

9. The method of expandingsheet metal, comprisin the constant drawing apart of unstrande margins of a stranded sheet, the

thereof, and to confine the lateral expansion to another portion of the sheet.

10. The method of expanding sheet metal, comprising the diflerentialf'lateral expan-' This is for the reason that there is no sudthe strands to compensate for the diflferem' tial expansion without longitudinal contraction. v

v 12. The method of expanding comprising the differential and. progressive lateral expansion of a stranded sheet, and the corresponding diiierential and progressive thinning and elongation of the strands to compensate for said differential expan 13. The method of expanding sheet metal, comprising. the alternate and difi'erential lateral expansion of difi'erent portions of a stranded sheet, and the differential rollin of the expanded sheet to harmonize and 4 equalize the difi'erentialexpansion thereof.

The fl qd gt xr d nssh stmetsk sheet metalfiria memes comprising the subjection of a stranded sheet to a difi'erential lateral expansion, and the rolling 0f the sheet by crowned rolls to harmonize the differential expansion thereof.

15. The method of forming expended sheet metal, comprising slitting a sheet to strands of progressively diminishing Width and difierentiafly expending said sheet progressively from the strand thereof.

In testimony whereof I affix my signature in presence of two Witnesses.

HENRY C. HERB. Witnesses:

GEO. N. Merino, J 12 Monmsom Wide to the narrow 

